A cough is one of the common presenting symptoms in the clinic and is associated with a number of respiratory and non-respiratory diseases. It can have a number of distinguishing characteristics such as quality, sputum production, timing, onset, duration and associated symptoms. The physiological mechanisms underlying cough involve a reflex arc with a command center in the medulla. Common non-respiratory causes include gastroesophageal reflux disease and postnasal drip, whereas, the most common respiratory etiologies are infectious diseases, chronic obstructive pulmonary disease, asthma and interstitial lung disease. Wheezes are high-pitched, loud sounds that usually accompany asthma, while stridor is most prominent with upper respiratory obstruction. In this article, physiology, different causes of cough and wheezing will be discussed in detail.

00:00
might be the diagnosis.
The past medical history is important, becauserespiratory disease can be a consequence or
related to previous medical problems. Andthere are numerous examples, but the common
important ones are asthma, which childhoodasthma often returns in an older adult and,
therefore, could explain somebody who's presentingwith cough or breathlessness at that point.
Previous tuberculosis for two reasons: Oneis that actually TB often causes chronic lung
damage, which can cause the presentation thatyou're reviewing the patient for there—hemoptysis,
for example—due to underlying bronchiectasiscaused by previous tuberculosis or a mycetoma.
And also, previous tuberculosis means thepatient could have—well, has latent tuberculosis
and therefore is at risk of reactivated tuberculosisdisease, which might explain their presentation.
Hay fever and eczema (atopy) we've alreadydiscussed as a risk for asthma. Cardiac problems
are important really as a differential diagnosisfor respiratory patients who are presenting
with dyspnea or edema. So if somebody's gota past history of hypertension, diabetes,
ischemic heart disease, all these are predisposedto left ventricular failure, which would be
a cause of breathlessness as a differentialdiagnosis of somebody presenting to a respiratory
clinic.
01:15
Previous cancer is important, because the
patient may be presenting with metastasesfrom the cancer now affecting the respiratory
system such as, for example, pleural metastasesand pleural effusion. Or because the treatment
that they receive for their cancer—and theclassic example for that would be radiotherapy
for breast cancer—can cause damage to theunderlying lung, and that might explain why
the patient has respiratory symptoms at thattime. And chemotherapy, for example, can cause
both widespread lung damage in the form ofinterstitial lung disease but also makes patients
more likely to get various types of infection,and that might be why they're presenting with
lung disease.
01:50
Patients with bronchiectasis: One of the major
causes is previous severe childhood infections,and so those would need to be discussed if
somebody might have bronchiectasis. And connectivetissue diseases such as rheumatoid arthritis,
systemic lupus erythematosus, dermatomyositis,systemic sclerosis: They are all associated
with various types of lung disease, specificallylung interstitial infiltrations, which could
be a differential diagnosis in somebody presentingwith fibrosis. And a very important point
is that premature birth and poor lung developmentin very early life actually, by reducing your
overall lung volumes, makes you more likelyto develop diseases such as COPD in the future.
And if somebody's presenting with relativelyearly onset of breathlessness, it would be
worth working out whether they had a prematurebirth that might have predisposed them to
an earlier problem than they otherwise wouldhave developed.
With lung disease, because the lungs are exposedto the environment, what you do in that environment
has a very big effect on the potential diseasesyou might have. And the most obvious example
for that is that if you smoke. But there areother substances which are relevant—for
example, if you smoke cannabis or if you injectdrugs. In addition, the jobs that you do can
expose you to various dusts and things whichmay be relevant for lung disease—the classic
example being asbestos exposure and the riskof asbestos pleural disease, the other main
example being pneumoconiosis, which are associatedwith mining and factory work.
But asthma can be made worse by antigens whichare present in your work environment, and
that's so-called occupational asthma. Andhypersensitivity pneumonitis is a problem
where you get lung interstitial… so youget interstitial lung disease due to inhalation
of an antigen to which you're allergic, andthat is often due to exposure to birds or,
if you're a farmer, due to fungi which growin the hay, etc. So it's very important with
respiratory disease—and specifically forinterstitial lung diseases, asthma, and patients
presenting with infiltrates in the lung—toidentify their occupational history and social
factors that might be relevant for their presentation.
04:27
Lastly, if you have a lung disease and you
are more breathless than you should be, thenthere is the issue about who's going to be
looking after you. If you're… have MRC Grade4, for example, and you're breathless on moving
around the house, who will do the houseworkfor you? Who will go and get the shopping
for you? And these issues are important anda part of the social history and need to be
discussed with the patient, so you get a fullfeel for the effects of whatever respiratory
disease they may have on their actual functionin life.
So to go into substance use, misuse, and abusein a bit more detail: Cigarette smoking is
associated with COPD but also… and lungcancer; everyone knows that. But it also massively
increases your chance of pneumonia. It makesasthma very difficult to control. It increases
your chance of pneumothorax. And it is associatedwith interstitial lung disease as well. Alcohol
is not a major problem for lung disease, apartfrom the fact that it makes you more likely
to get infections such as pneumonia or tuberculosis,and it makes you likely to get aspiration.
So it's a classic presentation is that somebodyhas been out for a drink in one night and
the next day presents having aspirated, witha pneumonitis affecting one lung.
Also, alcohol is a sedative, and that doescause problems for patients with sleep apnea
and other problems of ventilation of the lung,where sedatives make the ventilation… the
underventilation that's occurring even worse.
05:52
And patients with alcoholic liver disease
will present with pleural effusions. Recreationaldrugs other than smoking and alcohol—cocaine,
intravenous heroin, crack—they are all relevantfor lung disease. COPD, emphysema, asthma,
HIV infection, pneumothorax, lung infections,tuberculosis, bullae... They're all related
to recreational drug use, and as many patientsthat I see who have used to use recreational
IV drugs in their early life are now presentingwith emphysema or bullae in their later life,
age 40 to 50s.
06:31
So smoking history: This is described in pack
years. This is a vital part of the respiratoryhistory. You need to know whether the patient
has smoked in the past, is smoking now, orhas never smoked. So often when we ask a patient,
&quot;Are you a smoker?&quot; they say no. But thatcould be because they gave up smoking three
weeks ago. So you just need to define whetherit's ex-smoker or never smoked. And we describe
the cigarette exposure in pack years. Andthat is one pack smoked each day for a year
is one pack year. So for example if you havesomebody who smoked 10 cigarettes a day for
20 years, that's equivalent to 10 pack years.
07:13
If you have somebody who smoked for 30 years,
30 cigarettes a day, then that's 45 pack years.
07:18
In general, COPD and lung cancer, you normally
have to smoke around 20 pack years to getthe increased risk for developing both those
disease. That's a rule of thumb; there areexceptions to that. And certainly, it doesn't
mean you will get lung cancer or COPD if yousmoke 20 pack years; it just means your chance
of developing those diseases is much, muchhigher.
Treatment history and allergies: Well, youhave to know the patient's allergies if you're
going to give them… especially antibiotics.
07:49
Because penicillin allergy is not uncommon,
and you give somebody with a penicillin allergyan antibiotic which is penicillin-based, then
that is incredibly dangerous and potentiallyfatal error. So allergies: vital. You must
know… must ask specifically about allergies.
08:04
But also, drug diseases cause respiratory
problems. The commonest example, perhaps,may be ACE inhibitors, which are used for
hypertension, and they are a common causeof chronic, intractable cough. And unless
you take a good treatment history and askthe patient directly, you may not get the
fact that they're on an ACE inhibitor volunteered.
08:24
The treatment history also gives you the chance
to double-check their past medical history,because many patients won't mention the fact
that they have hypertension, but then whenyou ask them about what drugs they're on,
it turns out they're on antihypertensives.
08:36
That's a very common example of how patients
think about their diseases.
08:42
Family history for respiratory disease is
important in certain circumstances. Thereare diseases that run in families—-asthma,
for example—and there are inherited geneticdiseases, such as cystic fibrosis. And in
addition, prior tuberculosis exposure makesyou… through your family members makes you
likely to have latent tuberculosis, and thatmight reflect what's happening with your presentation
in a future life.
09:11
So just to summarize the main learning points
for the clinical assessment, the history sideof the clinical assessment:
1. A good history is essential and will helpyou identify what the medical problem is in
a very high proportion of patients who arepresenting. It will at least identify the
clinical question that needs to be answeredby targeted investigation. And this requires
a systematic approach to the history to ensureevery aspect is covered that might be important.
2. The demography, the social history, ofthe patient is important, because that does
identify whether they are at risk of certaindiseases. And you need to learn about what
those associations are so you can ask therelevant questions for people presenting with
specific problems.
09:58
3. You do need to know what causes the symptoms.
So you have to know what the common causesof cough are, what the common causes of breathlessness
are. Now fairly obvious, most of this, butif you don't know the important causes of
symptoms, then you will not be able to excludeor include those causes in a differential
diagnosis when discussing a problem with apatient. And that does include the rarer causes
as well, because part of the art of medicineis to make sure that you don't always make
the common diagnosis. So if a patient's presentingwith cough, say it's asthma. But in fact,
actually, it may not always be asthma. Thereare the occasional patients with rarer conditions
which may be coming, which you would missunless you knew that might be a presentation
for… a cause of cough.
10:50
4. One aspect that often is underdone by students
is the detail of the history of the presentingcomplaint. So I've discussed earlier when
talking about breathlessness: You need tofind out how long the patient's been breathless;
the periodicity—whether it's up and down,whether it's constant, whether it's progressive.
And actually ask very specific questions toget a full feel for how fast if it's progressive
it's deteriorating or how severe the breathlessnessis; what it stops them doing. And that needs
to be done for all the sort of symptoms that…all the symptoms that the patient's presenting
with. Obviously, this requires a bit of practice,and taking a good history which is fast, efficient,
and targeted to get the information you requirewill require a detailed underlying knowledge
about respiratory disease as well as constantpractice of actually the art of taking the
history from a patient.
11:50
Thank you.

About the Lecture

The lecture Past Medical and Social History – Lung Disease by Jeremy Brown, PhD is from the course Introduction to the Respiratory System.

Included Quiz Questions

Which of the following is an unlikely clinical association?

Night sweats and COPD

Emphysema and weight loss

Night sweats and tuberculosis

Ankle oedema and severe COPD

Which of the following aspects of the history is the least likely to be directly linked to the stated clinical presentation?

A history of alcohol abuse in a patient presenting with a 5 year history of progressive dyspnoea.

A history of hay fever and eczema in a 25 year old presenting with chronic cough.

A previous history of tuberculosis in a 39 year old presenting with recurrent haemoptysis.

A history of rheumatoid arthritis in a 72 year old presenting with chronic progressive dyspnoea.

Premature birth can cause predisposition to which lung disease?

COPD.

Asthma.

Tuberculosis.

Sarcoidosis.

Cystic fibrosis.

Pneumoconiosis is seen to occurs in which of the following occupations?

Mining.

Construction worker.

Car mechanic.

Carpenter.

Radiologist.

Patients with interstitial lung disease generally give a history of which substance abuse?

Tobacco.

Marijuana.

Alcohol.

Sugar.

Heroin.

Author of lecture Past Medical and Social History – Lung Disease

Jeremy Brown, PhD

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